Most engines will execute each code chunk in a separate new session (via a system() call in R), which means objects created in memory in a previous code chunk will not be directly available to latter code chunks. Note that you can use a named list to specify the paths for different engines. Knitr ::opts_chunk $ set( engine.path = list( python = '~/anaconda/bin/python', ruby = '/usr/local/bin/ruby' ))
To use a different language engine, you can change the language name in the chunk header from r to the engine name, e.g., The engines from theorem to solution are only available when you use the bookdown package, and the rest are shipped with the knitr package. Most engines have been documented in Chapter 11 of Xie ( 2015). Names(knitr ::knit_engines $ get()) # 'awk' 'bash' 'coffee'
